Variable-transmission gearing



y K. 1:.v JAMES vAnIALE TRANSMISSION emma 'Fired oet. 12, 1925' :ssheets-sheet 1 @Mn/WMM ay K. D. JAMES VARIABLE TRANSMISSION Gamme Filedoct'. 12. 1925 s sheets-snm 2" Inventor: Keith Dufamf' May 3, 1927.

K 1,626,611 K. D. JAMES VARIABLE TRANSMISSION GEARING Filed oct. 12,1925 a sheets-sheets Inventor: i/ezth D. James Patented May 3, 1927.

KEITH DUDLEY JAMES, OF-HOBART, TASMANIA, AUSTRALA.V l v'VARIABLE-TRANSMISSION GEARING.

Application filed october 12.1925, seriai No.` 61,9815, and in numanaAprii 24, 1,925.

. which will be capable of a. gradual and continuous variation of vspeedfrom zero upto i a maximum predetermined ratio lin both forward andreverseJ directions. y

f I accomplish the aboveinentioned ob3ect,

.by providingV a variable transmission gearl which comprises a drivingdisc adapted to be rotated directly by or through gearing from a drivingshaft, a. pair of frictiondiscs adapted to engage the face of thedriving disc,V one on each side of the centre thereof,

the saine being slidably mounted on but coiif strained to rotate with apair of gears supv ported in bearings arranged parallel to and inadvance of the face of the said driving disc, and two or more epicyclicgears mounted kon a rotatable transmissio-n member and adapted to engagethe firstmentioned gears. Means are provided whereby the friction discsmay be traversed in unison across the face of the driving disc wherebythey will be caused to rotate at differential speeds in opposite.directions in order to rotate the saidk cage through theepicyclicgears.

Means are provided for maintaining a con-i4 stant working pressure onthe driving disc to hold the same in gear and take up wear. Means areprovided also forenabling the driving disc to` automatically valignitself' with the faces of the friction ydiscs and thereby compensate forany irregularities in wear or manufacture. v

, In the following specification thev invention has been described withreference to drawings illustrating certain adaptations of the same tomotor propelled `vehicles but it will be readily understood that suchvadaptations are given by way of examples only and that the scope of theinvention is not confined thereto. 1

fn these drawings: Figure l is a view in sectional side eleva- `tion ofa variable transmission gear constructed in accordance with theinvention and adapted for use in a'motor propelled vehicle. i Y

Figure 2 is a view in sectional plan taken y on theline 2--2 of Figurel. .i

Figure 3 is a view in side elevationofv i one form of device designedyto control the transmission Age'arshow'n in Figure l.

Figures 45 and :5 are views in end eleva-5' tion and sideelevation,respectively,l of an,v alternative form ofcontrolmechanism.

Figures 6 and V7 are viewsin elevation of alternative devicesforap'plying andV'ma'in-H taining a working pressure between]- thedriving discl and frictionv discs.`

Figure 8 is a view in sectional plan' of i 7() ofa modified construction,of `the invention.

for transmitting heavy `drivesV and hereinfl after is fully described. ly

Referring tov Figures 1 and 2 of the drawings, vwherein a driving disc20 is adapted to be` driven lthrough a flexible or resilient. coupling`(such asa leather or Vfabricdiscand coupling flange 21) y.from thecrankshaft 22 of an engine (not shown) or other rotating drivingmember;Thedriving face ofv the said disc 2O is preferably provided withlreversible -I wearingA rings 23 removably 4attached thereto. 1 l, j y fThe disc 2O is provided'witha self-aligning anti-frictional thrustbearing 24 whichbears againstr theV concaved faceof aguidefmem-` ber 25slidably mountedv on afboss 26 which i is concentrically arranged .aboutthel p end of the crankshaft 22 and is rigidly attached to the insideofacasing 27 rsurrounding.and`

supporting the same.` A spherical grease or,

oil retaining member 28v is -attached to; tliey i' i rear ofthe saiddriving disc 20y in such ai,

manner that the said discy can oscillate slightly without interferingwith thetrans-v mission of power from the crankshaft 22,` and acentering pin- 29 having a ballsha-ped.

headis carried by the disc and is engaged. by a hole 30 formed axiallyinthe end of the crankshaft. A ypressure ring 3l is mounted freely.. onthesaid boss 26 at the rear of the guide inember25 -and the said ring isprof vided with a series of rollers` 2.9. adapted to traverse acorresponding series of'cam faces 32y arranged on a circular memberirigidly attached to the interior ofthe casing27.` y

Vthe ydriving disc-20) which are mounted jin suitable antifrictionbearings 37 positioned in'advance" thereof. The said bosses 36 areprovided with splines" 38 or yare yotherwise suitably' designed so thata pair of' `friction dis'csl`39 will be yfree to slide thereonE and atthev same time befconstrained to move an'- gularly therewith. i

The friction. discs 39 are madel preferably ofcast metal such as'aluminium andare provided with iangularly disposed. flanges one ofwhichis `removable, as shown, in' order thata iibre friction ring 40 may beinserted 4and p gripped therebetween. The

` fibrel friction rings may be split or alter- .with` the -saiid lforl41.

nativelymay be made in halves in order t facilitate 'fthe'fremoval ofthe samefrom the v'frictiony discs for the purpose of renewal.' i

A shifting fork 41iof suitable designis associated with the frictiondiscs :39 in such a `nfianner that they can be moved in vunisonbackwards and forwards across the face of the'driving disc forthe'purpose of varying the speedratio ofthe transmission gear, as

' desired.V i

' 'Theshifting forl` v4l isoperated ybyineans ofra screw `shaft 42 thescrew v42"*ther`eon havingv a' single or multiple start and the .f saidshaft is carried in bearings'llmountedin tliejgearcas'ing27, the s aidvsc rew beingfadapted to engage a corresponding nut 41 ,rigidly attachedto or formed integrally 'When this invention is applied to a ymoi toiqlcar'the-screw'may be rotated through universal jointsor iieXiloleVcouplings 44 and suitable s bevel lorvskew `gearing l45 from a controlleve`r`46, A(-see"lr"igi'ires-4y `and 5) positioned conveniently tothe'roperatorvor al' ternatively by'` a segmental member 47 mounted on ashaft inside column 47 which is supported in bearings 47-'arrangedparallel and` in close yproximity to 'thesteermg column y48 of the saidmotor caras shown in Figure 3, of the drawings;

A cage 49 formedv `n`two sections is.

mountedinbeari1igs-`50-lioused in a boX 5l rigidly" attached to the`casing 27 by means of bolts 52 and the said cage supports the innerends of the elongated bosses 36 of the bevel pinions 35 which are'located in the interior thereof. The cage is provided with adiametricallyy disposed pin 53 or two or more radially disposedpins-upon the ends of which are mounted epicyclic bevel pinions 54constantlyin mesh with the abovementioned pinions 35. A bevel crownwheel 55 is'rigidly secured to the said cage 49 and the same engages abevel pinion 56 formed onvv the end lofthespindle'57 which `in whichcase it would replace the gear-box and friction clutch vatpresent inuse, it being understood that as the driving `disc 20 rotates, thefriction discs` 39 in contact therewith' are rotated in opposite'directions; if the angular velocities of theffdis'cs 39 are equal,ywhich is the case whenfthe same are at equal distances from the-'centreof the driving `disc 20, the gearv is in the neutral position andtheepicyclic pinions 54 are merely rotated about their own axes noresultant movement beingfimparted to the cage 49 carrying the same. y

However, when the friction discs are traversed from the neutralpositionacross the face of the driving disc 20 by 'means` or theshifting fork-4l andthe mechanism'associated therewith as abovedescribed, they will' be caused to rotate at -vdiferentf speedsdepending on their respective distances from thev centre of the ldisc20, and 'the cage 49 carrying the epicyclic pinions 54'will be rotatedat half. the diHerence of the angular velocities" of the said frictiondiscs, as in ordinary differential gear mecha nism.` -Itwill ,be obviousthat the rotation of 'the driven shaft 57` will .bei reversed if the'friction discs'39 are moved across to the other side 'of the'neutralposition' on the driving disc 20. Suitable antifrictionloear-4 ings andlubrication devices are'employed so that losses through frictionmay'bereducedto a minimum and ventilation .and drain holes are providedin the casing '27.

In ythe form of control mechanism shown i in Figures'4 and 5 a verticalleverv 46 is pivotally mounted on a`pin"67 carriedon a member rigidlyattached to the casing 27 and positioned conveniently to the ldniver.The lever is provided 'with a curved toothed segment 68fwhich engages apinion 69 secured to the end of the screw shaft 42 which operates thevshifting forl; 41 or. alternatively the said pinion 69. may beyattachedy to a spindle [arranged in geared relationship therewith asshown in Figures 2 and S.

The face of the toothed segment 68 is preferably serratedhas shown at 70and a spring operated plunger 7l carried on a portion of the casing 27or member attached thereto is i adapted to frictionally engage andretain the same in anydesired posit-ion. v

"When this form of control is adopted, the

Y bearings 37 and 37.

. A v on the end of a rod 74 connected by universal or pivotaljointswiththe link`34 attached to -the periphery vof the pressure ring 31which carries the series of rollers 29" and is adapted toconstantly'engage the teeth of the fixed rack 72. A spring tensionedrack 75 movable in a guide 76 engages the other side of the pinion'73and exerts thereon aA constant force which is'transmitted to thepressure ring 31 thereby causing Vthe rollers 29 to mount or tend tomount the inclined vfaces 32 formed on the aforesaid stationary circularmember 33 and thereby exert an axial'force on the driving disc 20.

A plunger 77 is mounted on a guide' member 77 rigidly associated withthe fixed `rack 72 and one end of a spring`78 carried in a bore in themovable rack 75 bears thereon. An arm 79 is mounted on the guide memberand has a series of ratchet teeth formed thereon which'are adapted toengage a toothV 7 6 formed on or attached -to the guide member 7 6 insuch a mannerthat by raising or lowering the hand lever the drivercanapply greater or `less pressure to the driving disc 20. The spring 78 isof such strength that when it is compressed solid it 'exerts ythe corerect maximum pressure. Thelteeth on the arm 79 are maintained inengagement with the tooth 76 by a spring controlled thrust member 79. i

In a modification of the invention as shown in Figure 8 the variabletransmission gear is combined with the differential gear in the rearaxle of a motor car and is supported in a casing surrounding the saidback axle and preferably in the centre'thereof.

` The friction discs 39 are mounted 'on splines 38 formed on the hollowbosses 36 of the bevel'pinions35 which are carried in A cage '49 ispro-vided and is supported in antifriction bearings 50 carried by theinner ends of the said bevel pinions 35. y

The cage 49 is provided with a diametrically disposed pin 58 whichprojects through the same, and epicyclic bevel pinions 54 are mounted onantifrictional bearingsion the portion of the pin 58 extending beyondthe cage. The bevel pinions 54 are 'in constant engagement with theabovementioned bevel pinions 35 for the purpose hereinbefore described,and another series 'of epicyclic bevel pinions 59, comprising the usualldifferential or compensating gear, are mounted freely on the pin 58inside the cage 49 and the same are in'constant gear with va pair ofbevel gears 60 carried on splines formed onl the inner ends ofthedivided axle 61, which passes through the hollow bosses 36 ofthe bevelpinions v35 and the saidaxles are-provided with the usual road wheels(not shown).

In this design the periphery" of the pressure ring31 is provided witha'seriesof gear teeth 84, which may be straight but' are preferably ofhelical `design and thesaid.

ring is adapted to be rotatedb7 means `ofa corresponding pinion 84vmountedA on or formed integrally with a`spindle`83 whichis carriedA inbearings in 'the casing 27. f The spindle'83 is preferably connected toa pres-` sure control device of the type shown'in Figs ure 7 ,andhereinafterv fully described.,

When the periphery of the pressure ring 31 is provided with'a` series ofgear 'teeth 84 a mount'a'pinion 80 (see Figure 7) on a'member 81positioned conveniently to the driver. rlhe pinion 8Ov is mounted on aspindle 82 as illustrated in Figure 8 of the drawings, I

which is connected by universal joints or the l L like (not shown)` to.the spindley 83 carrying the pinion 84 in vmesh with the teeth 84 on thepressure ring 31 and the said pinion engages a rack 85 movablelintheguide mem` ber 8l to which pressure'is applied by means of a spring 86,the said pressure being `adjustable by the operation ofthe notched armIn order to obtain a quick releaseV (if `desired) for the pressurecontrol'devi'ce the notched arm 79 may be engaged by au oscillatable ormovable combination tooth and pedal 91 carried on the guide member 81 or72 and held in engagement with -7 9 by spring plunger 91. Alternativelya pad. 912 ima-y be formed integrally withmember 7 9 toenable quickrelease by foot pressure.

In another modification of the invention; especially' applicabley tolmachine tools and the like, see Figure 9 the. bevel pinions35 having theextended bosses 36 are mounted freely on a spindle 62supp`orted insuitable' bearingsv 63 and 63. The "said spindle is provided in thecentre` thereof with a pair of rradialpins v64 rigidlyA attached theretoor formedy integrally therewith, and the epieyclic bevel pinions-54aremounted freely. thereon, and the drive tothe operativey mechanism, maybe takenfrom .either end ofthe said spindle 62. The gearing runs in oiltight casing 632.- f I A hand lever 65 is provided to operate theshifting fork 41 for traversing the friction discs 39 'across thedriving disc20 and thus alter thevspeed ratio, and another hand lever 66is provided invorder toaljustthe pres'-v sure on the drivingdisc 2Oby'partia'lly rotating the pressure ring 31 carrying the rollers 29 asdescribed in reference in Figures 1, 2, and 8,.. f

shown in rieur-6.0i Figur@ 7 may be utilized. i I

Vy-In Figure l of the drawings, v.an application of the-invention is;illustrated which is especially adaptedV kfor the` transmission of heavydI'YS- l l l In this design twogpairs of friction discs v{jlQare mountedo neach side of the centre of thedrivingdisc 20`and in order to avoidfriction losses' through' slipping due tov their differenti angularvelocities each n pair 1s mounted freely on a bossor carrier 87wh1ch fisffree to slide axially on, but is constrained f two discs.

togmove angularlywith ithe elongated bosses 36 of ithebevel pinions 35.The bosses 88 of the frietionpdiscs 39,2are provided with bevel teethhaving a commonapex point andthe same are constantly in mesh withepicyclic pinionsf-SQ mounted freely on pins proradiallyfrom the saidvboss por carrier 87' such -a manner that when the fr iction'discs39 arein contact with the drivr narybrakes.` The ldevice shown in Figure 8maybe vadapted to a four vwheel drive if desired, in which case it ispreferably positioned approximately'in the centre of the chassisandsuitable:4 bevel 'pinions arey provided at the-ends of the jack shafts6l and corresponding bevel piniol'isare mounted on individual driveshafts for each of the said w-heels. Brakes may. be fitted outside thelast mentioned gears onthe jack shafts 6l instead, of on the roadwheels. y

A variable speed gear constructed and arranged in accordance with theinvention will bey found comparatively .economical to manufacture andefficient in operation as the motor ycar or othervehicle or machine inwhich it is embodied can'start under load with ythe power unit runningat maximum speed, if desired, ythus enabling economy of power to beeffected anda relativelylower powered engine vor power unit to beutilized than hasfhitherto been possible*l I C12111, -1. Ay variablepower transmission gear comprising a ca sing, a1 driving shaft havingone end-revolvably supported vwithin the casing, av driving ldisc, aflexible coupling connecting-the driving disc tothe driving shaft7 aself-aligning thrust bearing located ybetween the' casing and thevdriving clics,

means for exerting an end thrust' on the selfaligning bearing,` a1.ypair rof oppositelynlis.- posed bevelgear wheelshaving elongated bossesprojecting fromfthe outer faces there'- of, bearingsfmountedin thecasing and rotatablyl supporting the lelongated bosses, ,a

pair of friction discs slidably and non-ro 2. A variable powertransmission gear comprising casing, a drive shaft projecting into thecasing, ra driving V.dise flexibly coupled to the inner end of the driveshaft, a1` hole formed axially in the end of the drive shaft, a pinprojecting rearwardly from the `centre of lthe .driving disc,` laspherical head lon the said lpin engaged by the hole in the drive shaft,a boss fitted to the casing and surrounding the drive shaft, a pressurering rotatively mounted on the said boss, a selpf-aligning thrustlbearing located between .the pressure ringv and the back of the drivingdisc, rollers on the thrust ring7 a series of camv faces von the casingand disposed in the path of the rollers on the pressure ring, means. forrotating .the pressure ring, a pair of vopposed bevel gear wheels havingelongated bosses supported in bearings mounted onthecasing,

friction discs slidably i and. non-rotatively l supported on theyelongated bosses vofthe bevel gear vheelssa1d friction discsbearingagainst the opposite sides of the centre l of the driving disc,' a cagerotatively supported'about the bevel gear wheels7 epicyelic gear wheelssupportedwvithin the cage and meshing with the bevel gea-r wheels, acrown wheel on the oage,. and al pinion mounted on a driven shaft .andmeshing with the crown wheel.

In a variable power transmission gea-r as claimed in claim 1,'a casing,a drive shaft projecting into the casing, a. driving disc fiexiblyrcoupled to the inner end of the drive shaft,la.hole formed axially intheend of the kdrive shaft, a pin projecting rearwardly from the centre ofthe driving disc, a spherr ca'l head on the said pin engaged by the`hole in the driveshaft, a boss fitted to the casing and surrounding thedriveeshaft, a pressure ring rotatively mounted on the said boss, aself-aligning thrust bearing located between the pressure ring and the:back of the driving disc, rollers on the thrust ring, a series of camfaces on the casingand Ldisposed in the path ofthe rollers onkthepressure ring, and means for rotating the .pressure ring. v l e.

'1l-In a variable power transmission gear wherein .a rotatively mounteddriving disc is thrust against a pa'ir of friction discs associated withmeans for transmitting motion to a driven shaft, a casing, a driveshaft' projecting into the casing, a flexible coupling connecting thedrive shaft to the driving disc, a boss fitted to the casing andsurrounding the drive shaft, a'pressure ring rotatively mounted on thesaid boss, a self-aligning thrust bearing located between the pressurering and the back of the driving disc, cam shaped bearing faces for thepressure ring, a xed rack, a pinion engaging the fixed rack, a movablerack meshing with the teeth on the opposite side of the pinion, a linkconnection between the pressure ring and the pin supporting the saidpinion, and means for reciprocating the movable rack in opposition tospring pressure, substantially as described.

5. In a variable `power transmission gear wherein a rotatively mounteddriving disc is thrust against a pair of friction discs associated withmeans for transmitting motion to adriven shaft, a casing, a drive Shaftprojecting into the casing, a flexible coupling connecting the driveshaft to the driving disc, a boss fitted to the casing and surroundingthe drive shaft, a pressure ring rotatively mounted on the said boss, aself-aligning thrust bearing located between the pressure ring and theback of the driving disc, cam shaped bearing faces for the pressurering, a fixed rack, a pinion engaging the.

fixed rack, a movable rack meshing with the teeth on the opposite sideof "the pinion, a link connection between the pressure ring and the pinsupporting the said pinion, a fixed guide pin, a bore formedlongitudinally in the movable rack and accommodating the fixed guidepin, a compression spring surrounding the guide pin, a plunger mountedon the guide pin and adapted to move freely within the bore,and a leverslidably mounted on the guide pin and having notches adapted to engage axed retaining member, substantially as described.

6. In a variable power transmission gear wherein a rotatively mounteddriving disc is thrust against a pair of friction discs assoi ciatedwith `means for transmitting motion to a driven shaft, a ycasing forthev gear, a drive shaft projecting into the casing, a flexible couplingconnecting the drive shaft tor the driving disc, a boss fitted to thecasing and surrounding the drive shaft, a pressure ring rotatativelymounted on the said boss, a self-aligning thrust bea-ring located be'-vtween the pressure ring and the back of the operate the rack, andtoothed notches and a pawl for retainingthe control lever in an adjustedposition. L

7. In a variable power transmission gear as claimed in claim 6 footcontrolled means for releasing the control rlever to removev pressurefrom the driving disc.

8. In a variable `power transmission gear wherein a rotatively mountedvdriving disc' is thrust against a kpair of friction discs `associatedwith means, for transmitting motion to a driven shaft, a shifting forkfor traversing the vfriction discs across the face of the driving disc,a screw engaging a correspondingly threaded portion of the shiftingfork, a pinion fitted to the spindle'carrying the 'la l screw, a secondpinion meshing with the first mentioned, pinion, a spindle carrying the`second mentioned pinion, a flexible connectionv between the spindle anda rotating shaft, and means fitted to the steering. column of amotor-car for operating gearing for rotating the said shaft.

signature.

In witness whereof I hereunto ailix my`

